Realism in Virtual Reality

In this paper we want to present the state-of-the-art in providing realism in virtual environments. Techniques will be discussed to increase visual and auditory presentation. The behaviour of virtual worlds - a further demand on realism - is introduced and interaction techniques are explained with regard to intuitive understanding. Finally, we explain some applications in virtual environments which aim for a high degree of realism. As a conclusion we try to point out that realism (or a realistic impression) is subjective and heavily depending on the user himself

Fabrication and characterisation of Cu(In,Ga)Se-2 solar cells on polyimide

Solar cells with the structure ZnO:Al/i-ZnO/CdS/Cu(In,Ga)Se-2/Mo/polyimide were examined using a range of techniques. The elemental composition of the Cu(InGa)Se-2 (CIGS) layers, their crystalline structure and optical properties were studied. Photoluminescence (PL) spectra of the CIGS absorber layers were studied as functions of temperature (4.2-240 K) and excitation power density. The band gap energy E-g of the CIGS layers was determined by employing photoluminescence excitation (PLE) spectroscopy. The influence of sodium incorporation on the PL properties of CIGS was analysed. Correlations of the optical properties of the CIGS absorber layers and the photovoltaic parameters of the solar cells were revealed